Bi-directional self-energizing gaskets

Abstract

A heat exchanger includes a shell. A tubesheet is mounted to the shell. A plurality of tubes extend from the tubesheet and into the shell for heat exchange between a first fluid within the tubes and a second fluid in the shell outside the tubes. The tubesheet divides an interior of the shell into a heat exchange chamber where the tubes can exchange heat with the second fluid, an inlet-outlet chamber for the first fluid to enter and exit the tubes. A breech lock locks the tubesheet within the shell. A bi-directionally self-energizing gasket is seated between the tubesheet and the shell to seal the heat exchange chamber from the inlet-outlet chamber. The gasket is configured to be self-energizing to seal regardless of whether there is a higher pressure in the heat exchange chamber or in the inlet-outlet chamber.

What is claimed is: 
     
       1. A heat exchanger comprising:
 a shell; 
 a tubesheet engaged to the shell, wherein a plurality of tubes extend from the tubesheet and into the shell for heat exchange between a first fluid within the tubes and a second fluid in the shell outside the tubes, wherein the tubesheet divides an interior of the shell into heat exchange chamber where the tubes can exchange heat with the second fluid, an inlet-outlet chamber for the first fluid to enter and exit the tubes; 
 a breech lock locking the tubesheet against the shell, wherein the breech lock is spaced apart from the tubesheet across the inlet-outlet chamber; and 
 a bi-directionally self-energizing gasket seated between the tubesheet and the shell to seal the heat exchange chamber from the inlet-outlet chamber, wherein the gasket is configured to be self-energizing to seal regardless of whether there is a higher pressure in the heat exchange chamber or in the inlet-outlet chamber where the pressure loads are exerted in a radial direction, 
 wherein the gasket includes an annular main body, and wherein the gasket is engaged axially between an annular face of the shell and an annular face of the tubesheet, wherein the main body of the gasket includes a radially inward opening self-energizing feature configured to increase sealing engagement with pressure the heat exchange chamber, wherein the self-energizing feature includes a pair of axially spaced ridges extending from the main body of the gasket on either side of one and only one annular pocket that opens radially outward from the main body of the gasket, wherein the main body of the gasket includes a radially outward opening self-energizing feature configured to increase sealing engagement with pressure in the inlet-outlet chamber, wherein the self-energizing feature includes a pair of axially spaced ridges extending from the main body of the gasket on either side of one and only one annular pocket that opens radially inward from the main body of the gasket. 
 
     
     
       2. The heat exchanger as recited in  claim 1 , wherein the shell includes an inlet and an outlet for the first fluid, wherein the inlet-outlet chamber includes an inlet and an outlet for the second fluid, wherein the inlet-outlet chamber is subdivided by a plate into an inlet section and an outlet section, and wherein each of the tubes has an inlet through the tubesheet in fluid communication with the inlet section and an outlet through the tubesheet in fluid communication with the outlet section. 
     
     
       3. The heat exchanger as recited in  claim 1 , wherein the self-energizing feature includes a pair of axially opposed annular channels in the main body of the gasket proximate the annular pocket to facilitate flexure of the ridges for self-energized sealing of the ridges against the shell and the tubesheet, respectively. 
     
     
       4. The heat exchanger as recited in  claim 1 , wherein the self-energizing feature includes a pair of axially opposed annular channels in the main body of the gasket proximate the annular pocket to facilitate flexure of the ridges for self-energized sealing of the ridges against the shell and the tubesheet, respectively. 
     
     
       5. The heat exchanger as recited in  claim 1 , wherein the gasket includes a stainless steel material. 
     
     
       6. A gasket comprising:
 a bi-directionally self-energizing main body, wherein the main body is configured to be self-energizing to seal regardless of with pressure from a first direction and/or from a second direction opposite the first direction where the pressure loads are exerted in a radial direction, wherein the main body is annular, wherein the main body includes a radially inward opening self-energizing feature configured to increase sealing engagement with pressure in a heat exchange chamber, wherein the self-energizing feature includes a pair of axially spaced ridges extending from the main body of the gasket on either side of one and only one annular pocket that opens radially inward from the main body of the gasket, wherein the gasket includes a radially outward opening self-energizing feature configured to increase sealing engagement with pressure in a inlet-outlet chamber, wherein the self-energizing feature includes a pair of axially spaced ridges extending from the main body on either side of one and only one annular pocket that opens radially outward from the main body. 
 
     
     
       7. The gasket as recited in  claim 6 , wherein the self-energizing feature includes a pair of axially opposed annular channels in the main body proximate the annular pocket to facilitate flexure of the ridges for self-energized sealing of the ridges. 
     
     
       8. The gasket as recited  claim 6 , wherein the self-energizing feature includes a pair of axially opposed annular channels in the main body proximate the annular pocket to facilitate flexure of the ridges for self-energized sealing of the ridges. 
     
     
       9. The gasket as recited in  claim 6 , wherein the main body includes a material including at least one of steel, stainless steel, delrin, plastic, bronze, and/or rubber.